7.20 August 19, 2014
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Top new questions this week:
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[Is this 30% slowdown in Mathematica 10 due to DownValues lookup
time?]\url{http://mathematica.stackexchange.com/questions/57301/is-this-30-
slowdown-in-mathematica-10-due-to-downvalues-lookup-time}
Running several numerical self-programmed packages I realized already
some time ago that Mathematica 10 needed between 20 and 40% more time.
I did already report this of course with a simple example ...
- asked by Rolf Mertig (26 votes)
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[2D random walk within a bounded
area]\url{http://mathematica.stackexchange.com/questions/57561/2d-random-wa
lk-within-a-bounded-area}
I want to simulate a random walk on two dimension in a bounded area such
as a square or circle. I am thinking of using If statement to define a
boundary. Is there a better way to define a bounded ...
- asked by yashar (20 votes), answered by Pickett (21 votes)
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["Indexing" a
vector]\url{http://mathematica.stackexchange.com/questions/57613/indexing-a
-vector}
I need to "index" a vector according to the first occurence of its
distinct elements.
I have written
index[list_] :=
Module[{x = list, p},
p = Flatten /@ Map[Position[x, #] &, ...
- asked by eldo (13 votes), answered by kguler (18 votes)
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[Convert spectral distribution to RGB
color]\url{http://mathematica.stackexchange.com/questions/57389/convert-spe
ctral-distribution-to-rgb-color}
Presume I have a spectrum as a function of wavelength (an example being
the blackbody spectrum):
I want to convert that to a single RGB color to display on-screen, i.e.
the "color" of that object ...
- asked by Guillochon (13 votes), answered by Sjoerd C. de Vries (11
votes)
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[Why does Mathematica simplify
$x/x\to1$?]\url{http://mathematica.stackexchange.com/questions/57489/why-do
es-mathematica-simplify-x-x-to1}
If I enter x/x, I get 1. Such behavior leads to this:
Simplify[D[Sqrt[x^2], x, x]]
0
The same would be even if I use Together instead of Simplify.
One could then think that $\sqrt{x^2}$ is ...
- asked by Ruslan (11 votes), answered by Jens (5 votes)
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[Manipulate crashes after running 4
minutes]\url{http://mathematica.stackexchange.com/questions/57247/manipulat
e-crashes-after-running-4-minutes}
The following code generates the familiar 3D-plot:
Manipulate[
Plot3D[Sin[x a] - Cos[y ], {x, -10, 10}, {y, -10, 10},
ColorFunction -> "TemperatureMap"], {a, -2, 2, 0.1}]
However ...
- asked by MathLind (10 votes), answered by Szabolcs (2 votes)
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[Incompatible InterpolatingFunction between V9 (and earlier) and
V10]\url{http://mathematica.stackexchange.com/questions/57608/incompatible-
interpolatingfunction-between-v9-and-earlier-and-v10}
I am encountering compatibility issues when loading DumpSave(d)
definitions in V10 that have been created with earlier versions. V10
appears to be unable to digest `InterpolatingFunction from earlier ...
- asked by Markus Roellig (10 votes), answered by Mr.Wizard (4 votes)
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Greatest hits from previous weeks:
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[Marking points of intersection between two
curves]\url{http://mathematica.stackexchange.com/questions/10472/marking-po
ints-of-intersection-between-two-curves}
I'm trying to illustrate the solutions numerically and graphically for
an equation such as Tan[x] == x. I think I did everything ok except I
wanted to mark each intersection between Tan[x] and x.
...
- asked by fiz (24 votes), answered by belisarius (31 votes)
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[How to find all the local minima/maxima in a
range]\url{http://mathematica.stackexchange.com/questions/5575/how-to-find-
all-the-local-minima-maxima-in-a-range}
I want to find :
all local maxima in range
all local minima in range
>From those points I can interpolate and combine functions upper and
lower boundary. What I am really interested in, is the ...
- asked by Margus (38 votes), answered by Daniel Lichtblau (40 votes)
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Can you answer these?
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[Is it possible to Compile the function with string
argument?]\url{http://mathematica.stackexchange.com/questions/57355/is-it-p
ossible-to-compile-the-function-with-string-argument}
As we can see from the Compile documentation, the typical arguments for
Compile should be Integer, Real, Complex and True | False:
Is it possible to use a String as argument type for Compile?
May ...
- asked by Rom38 (2 votes)
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[Functional-Style Fixed-Length Queue
Object?]\url{http://mathematica.stackexchange.com/questions/57539/functiona
l-style-fixed-length-queue-object}
Following up on question Side-effecting an array in an association? and
@Mr.Wizard's answer in there, I'm modernizing and tweaking Daniel
Lichtblau's efficient queues and ran into a little roadblock.
...
- asked by Reb.Cabin (2 votes)
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[Adding an unused column creates an error in
JoinAcross]\url{http://mathematica.stackexchange.com/questions/57345/adding
-an-unused-column-creates-an-error-in-joinacross}
I'd been having trouble using JoinAcross on two datasets. After going
through the answers to my original question and fixing my code, I find
I'm now having a problem that I think is being caused by ...
- asked by Mitchell Kaplan (2 votes)